Hi Matt
I purchased a copy from Bintel a few years ago. I just looked at their website and they show it for $85.00.
https://www.bintelshop.com.au/welcome.htm
"The Messier Objects
O'Meara. The most widely observed objects in the sky. This book provides a fresh perspective on these famous objects. new drawings, new data, new charts. 304pp HC
$85.00"
It is a lovely book to browse and dip into, quite timeless in spite of the incredible advances in 'scopes and imaging since it was first published.
Cheers
Dennis